Roof bolter

ABSTRACT

A bolter ( 10 ) intended to receive a drill bit for the purposes of drilling a hole in a surrounding rock structure. The bolter ( 10 ) includes a telescopic leg ( 12 ) extending from a base ( 11 ). The base ( 11 ) is provided with a face ( 30 ) that is to receive a duct member ( 31 ). The duct member ( 31 ) provides for the delivery of a drive fluid (such as air) to the motor ( 29 ).

FIELD

The present invention relates to bolters employed in the mining industryand more particularly but not exclusively to roof bolts.

BACKGROUND

A roof bolter is a pneumatically or hydraulically driven piece of miningequipment. Bolters are used to install bolts in a mine roof, however insome instances roof bolts are also equipped with a drill bit to form thehole in which the bolt is to be inserted.

A disadvantage of known roof bolters is that they are generally adaptedto suit a particular drill bit and/or bolt. Accordingly a variety ofbolters need to be manufactured to suit the drill bits and variousbolts.

OBJECT

It is the object of the present invention to overcome or substantiallyameliorate the above disadvantage.

SUMMARY

There is disclosed herein a bolter to receive a driving fluid underpressure and a flushing fluid under pressure, the bolter including:

a base

a telescopic leg having a longitudinal axis, a lower portion to engage afloor surface, and an upper portion supporting the base, with thedriving fluid causing telescopic extension of the leg to raise the base;

a chuck mounted on the base and to engage a drill bit or bolt, the chuckbeing rotatable a chuck axis to drive the bit or bolt, the chuck axisbeing generally parallel to the leg axis;

a motor mounted on the base and drivingly coupled to the chuck to causerotation thereof, with the motor being driven by said driving fluid;

a control assembly manipulated by an operator to control delivery of thedriving fluid to the motor and leg; and wherein

said base includes a fluid delivery face to which ducting to receive thedriving fluid extends, with the ducting being connectable so that thedriving fluid flows past said face to be delivered to the motor.

Preferably, the face is adapted to receive a flow directing member toprovide for the flow of said drive fluid to said motor.

Preferably, the bolter includes an arm pivotally attached to the basefor angular movement about an axis generally normal to said longitudinalaxis, with the arm including the control assembly so that an operatormay control the bolter by manipulating the arm.

There is further disclosed herein, in combination the above bolter andflow direction member.

Preferably, said flow direction member includes ducting to provide forthe flow of the driving fluid to and from the motor.

Preferably, the flow direction member includes a muffler through whichdriving fluid leaving the motor is exhausted to atmosphere.

Preferably, said flow direction member includes a valve assembly toprovide for the delivery of the driving fluid to said motor so that themotor may be driven in a first direction or a direction opposite saidfirst direction.

Preferably, said valve assembly includes a casing and a rotary valvemember located in the casing and moved angularly to provide for deliveryof the driving fluid to said motor so that said motor can be selectivelydriven in either direction.

Preferably, said valve includes a movable valve member, said membervalve has a drive first position providing for the delivery of drivingfluid to drive the motor in said first direction, and a drive secondposition providing for the delivery of the drive fluid to drive themotor in said opposite direction.

Preferably, the movable valve member is movable to a third position atwhich the drive fluid provides for the injection of a resin by thebolter.

Preferably, a lock assembly operable to engage the chuck preventingrotation thereof relative to the base.

Preferably, the flow direction member includes a valve operable toactivate the motor to rotate the chuck, in a predetermined direction,and also operable to cause engagement of the lock member to preventrotation of the chuck relative to the base.

Preferably, the valve is operable to activate the motor to rotate thechuck in a direction opposite to said predetermined direction.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred form of the present invention will now be described by wayof example with reference to the accompanying drawings wherein:

FIG. 1 is a schematic isometric view of a roof bolt assembly;

FIG. 2 is a schematic side elevation of the bolter of FIG. 1;

FIG. 3 is a schematic a side elevation of the roof bolter of FIG. 1 inan extended configuration;

FIG. 4 is a schematic parts exploded isometric view of the bolter ofFIG. 1;

FIG. 5 is a schematic sectioned side elevation of the bolter of FIG. 1;

FIG. 6 is a schematic sectioned plan view of the bolter of FIG. 1;

FIG. 7 is a schematic isometric view of a modification of the bolter ofFIG. 1;

FIG. 8 is a schematic side elevation of the bolter of FIG. 7;

FIG. 9 is a schematic parts exploded isometric view of the bolter ofFIG. 7;

FIG. 10 is a schematic sectioned side elevation of the bolter of FIG. 7;

FIG. 11 is a schematic plan view of the bolter of FIG. 7;

FIG. 12 is a schematic isometric view of a modification of the bolter ofFIG. 1;

FIG. 13 is a schematic side elevation of the bolter of FIG. 12;

FIG. 14 is a schematic parts exploded isometric view of the bolter ofFIG. 12;

FIG. 15 is a schematic sectioned side elevation of the bolter of FIG.12;

FIG. 16 is a schematic sectioned plan view of the bolter of FIG. 12; and

FIG. 17 is a schematic sectioned plan view of a valve employed in thebolter of FIG. 7 and the bolter of FIG. 12.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIGS. 1 to 6, there is schematically depicted a roof bolter 10. Theroof bolter 10 is intended to receive a drill bit for the purposes ofdrilling a hole in a surrounding rock structure, with the drill bit thenbeing removed and a roof bolt engaged and inserted in the hole by theroof bolter 10. In some instances a cartridge is to be inserted in thehole and then the roof bolt inserted thereafter and rotated to cause thecartridge to rupture so that the resin surrounds the roof bolt. Uponsetting of the resin the bolt is then anchored to the surrounding rockstructure.

The bolter 10 includes a base 11 that is supported by a telescopic leg12. The telescopic leg 12 has a plurality of sections 13 that aretelescopically received within each other and that are extendable to theconfiguration as shown in FIG. 3. The lowermost section 13 has a floorengaging part 14 that aids in securely engaging the floor surface of amine. The uppermost section 13 is attached to the base 11 so that upontelescopic extension and retraction of the leg 12, the base 11 is raisedand lowered.

Pivotally attached to the base 11 is a control arm 15 having a pair ofhandles 16 that are gripped by an operator. The operator, bymanipulation of the arm 15, controls and operates the bolter 10.Typically adjacent one of the handles 16 is trigger 17 that is caused tomove by the operator, which in turn causes operation of the bolter 10,in particular the leg 12. Typically the bolter 10 would receivehydraulic fluid or air under pressure which acts as a driving fluid forthe bolter 10. The bolter 10 would also receive a flushing fluid (aliquid such as water) that would be delivered to the interior of thedrill bit and used to flush the hole being drilled by the drill bit. Thedriving fluid and flushing fluid would be connected to the bolter 10 bycouplings 18. The trigger 17 operates valves, at the operators end ofthe control arm 15, that provide for the flow of the driving fluid andflushing fluid to the base 11 and leg 12. The valves are operated bylevers 41 and 42.

The arm 12 is pivotally attached to the base 11 for angular movementabout an axis 20 provided by a pivot member 21. The pivot member 21 alsoconnects various ducting in the arm 15 to ducting in the base 11 for thetransfer of the driving fluid and flushing fluid thereto.

Attached to the base 11 is a further handle 19.

Mounted on the base 11 is a chuck 22 that is rotatably driven about anaxis 23 that is also the longitudinal axis of the leg 12. Fixed to thebase 11 and surrounding the chuck 12 is a guard (shield) 24. The axis 23is generally normal relative to the axis 20.

The chuck 22 is turned by a shaft 25 engaged within the centre spline 26of a ring gear 27. The gear 27 is driven by a further gear 28 which inturn is driven by a motor 29. The motor 29 is operated by the drivingfluid. Upon the driving fluid under pressure being delivered to themotor 29, the motor 29 drives the gears 28 and 27 and therefore thechuck 22 angularly about the axis 23.

The base 11 provides exhaust ducting for the motor 29, with the ductingextending to a face 30 of the base 11. Attached to the base 11 so as toabut the face 30 is a duct member 31 that communicates with ductingextending from the arm 15 to direct the driving fluid to the motor 29,and to receive exhaust fluid from the motor 29. In this embodiment, themember 31 also acts as a muffler as exhaust from the motor 29 is ventedto atmosphere.

In the above described embodiment, the driving fluid is compressed air.The motor 29 is a gear motor including a pair of rotatable meshinglyengaged gears 32 which are caused to rotate in a predetermined directionupon the compressed air being delivered thereto. The above describedpreferred embodiment has the chuck 22 driven in one rotational directiononly, with a flushing fluid (typically water) being delivered to apassage 33 in the chuck 22 for delivery to the longitudinal passage ofthe drill bit engaged with the chuck 22.

In the embodiment of FIGS. 7 to 11, the bolter 10 is provided with avalve 34 (further duct member). The valve 34 is bolted to the face 30 soas to communicate with ducting extending from the handle 15 so that thecompressed air is delivered to the valve 34. The valve 34 includes abody 35 within which there is supported for angular movement a movablevalve element that is caused to move angularly about an axis 36. Themovable valve element has a number of passages that provide for thedelivery of compressed air to the motor 29, and the ducting of exhaustair from the motor 29 to a muffler incorporated in the valve 34. Thevalve 34 is described more fully with reference to FIG. 17.

The valve 34 provides for the delivery of compressed air to the motor 29so that the motor 29 can be driven in either rotational direction.Accordingly in the embodiment of FIGS. 9 to 11, the chuck 22 can bedriven rotationally in either direction and again a flushing fluid suchas water is delivered to the chuck.

Further in respect to this embodiment, there is attached to the base 11a pump 37 that receives the driving fluid (air) and delivers water(flushing fluid) to the interior passage 32 at a higher pressure toprovide for the injection of resin to the internal longitudinal passagein a bolt mounted in the chuck 22.

In this embodiment, the bolter 10 receives a self drilling roof bolt.The bolter 10 has the chuck 22 rotated in a first direction for the selfdrilling bolt to drill into the rock layer. Once the rock bolt haspenetrated a desired depth, resin is injected through the bolt andallowed to set to secure the bolt to the surrounding rock layer.Thereafter the chuck 22 is caused to rotate in the opposite angulardirection to tension the bolt. During the drilling operation water ispumped longitudinally through the bolt to flush the hole being drilled.The rock bolt employed with this embodiment includes a firstlongitudinal passage that has a flexible closed tube of resin, with anannular passage surrounding the central passage, with the annularpassage receiving the flushing fluid. When the pump 37 is activated,water under pressure is delivered to the central passage and rupturesthe tube of resin and forces the resin out of the bolt and into the areasurrounding the bolt adjacent the rock surface. The resin is thenallowed to set.

The pump 37 receives the water under an initial pressure, and deliversthe water to the chuck 22 and a higher pressure. This enables injectionof the resin longitudinally through the bolt. It should further beappreciated that in respect of this embodiment, the bolt is insertedusing the bolter 10 and the resin injected, with the bolt then beingtensioned once the resin has set.

In the embodiment of FIGS. 14 to 17, the bolter 10 includes the chuck 22of the embodiment of FIG. 1 and the valve 34 of the embodiment of FIG.7. However in this embodiment, there is mounted in the base 11 a lockmember 38 that is selectively moved into engagement with the gear 27 toprevent movement thereof and therefore to prevent movement of the chuck22. Accordingly the bolter 10 may be employed to perform a finaltensioning of the roof bolt.

In FIG. 17, there is schematically depicted the valve 34. The valve 34includes an angularly movable valve element 39 that is movable angularlyabout the axis 36 between a first position, a second position and athird position. This is achieved by a pair of cables 40 that extend toadjacent the handle 16 at which there is located levers 41 and 42 thatcause movement of the cables 40 and therefore rotation of the element39.

In the embodiment of FIG. 7, the valve element 39 (as shown in FIG. 17)is moved into a position (first position—drive first position) at whichducting is connected to deliver compressed air to the motor 29 to causerotation thereof in a predetermined direction to rotate the selfdrilling bolt to drill the hole, a further position (secondposition—resin injection position) at which air is delivered to the pump37 to cause injection of the resin, and a still further position (thirdposition—drive second position) at which the self drilling bolt isrotated in the reverse direction to tension the bolt once the resin hascured. In the embodiment of FIG. 12, the valve element 39 (as shown inFIG. 17) is movable between a position (first position) at which thechuck 22 is rotated in a predetermined direction to rotate the drill bitto drill the hole, a further position (second position) at whichcompressed air is delivered to an actuator to cause engagement (anddisengagement) of the lock member 38, and a still further position(third position) to rotate the chuck 22 to tension the bolt.

In use of the bolter 10 of FIGS. 12 to 17, a drill bit is inserted inthe chuck 22, and a passage formed in the adjacent rock layer. Once thepassage is formed, the drill bit is removed and a tube of resin insertedin the passage. The rock bolt is then inserted so as to move the tube ofresin to the remote end of the passage, with the rock bolt then beingoperated to rupture the tube. The rock bolt is mounted in the chuck 22and rotated to cause distribution of the resin. The rock bolt 10 is thenrotated in the opposite direction to the drilling direction to tensionthe bolt once the resin sets. Final tensioning is achieved by manuallyangularly moving the roof bolter 10 about the axis 23 once the lockmember 38 is engaged with the gear 27.

An advantage of the bolter 10 of the above described preferredembodiments, is that the bolter 10 is adapted, by interchanging the ductmember 31 with the further duct member (in the form of the valve 34),and by adding or removing the pump 37 to be used with a variety of rockbolt systems.

1. A bolter to receive a driving fluid under pressure and a flushingfluid under pressure, the bolter including: a base a telescopic leghaving a longitudinal axis, a lower portion to engage a floor surface,and an upper portion supporting the base, with the driving fluid causingtelescopic extension of the leg to raise the base; a chuck mounted onthe base and to engage a drill bit or bolt, the chuck being rotatableabout a chuck axis to drive the bit or bolt, the chuck axis beinggenerally parallel to the leg axis; a motor mounted on the base anddrivingly coupled to the chuck to cause rotation thereof, with the motorbeing driven by said driving fluid; a control assembly manipulated by anoperator to control delivery of the driving fluid to the motor and leg;and wherein said base includes a fluid delivery face to which ducting toreceive the driving fluid extends, with the ducting being connectable sothat the driving fluid flows past said face to be delivered to themotor.
 2. The bolter of claim 1, wherein the face is adapted to receivea flow directing member to provide for the flow of said drive fluid tosaid motor.
 3. The bolter of claim 1, further including an arm pivotallyattached to the base for angular movement about an axis generally normalto said longitudinal axis, with the arm including the control assemblyso that an operator may control the bolter by manipulating the arm. 4.The bolter of claim 1, including the flow direction member.
 5. Thebolter of claim 4, wherein said flow direction member includes ductingto provide for the flow of the driving fluid to and from the motor. 6.The bolter of claim 4, wherein the flow direction member includes amuffler through which driving fluid leaving the motor is exhausted toatmosphere.
 7. The bolter of claim 4, wherein said flow direction memberincludes a valve assembly to provide for the delivery of the drivingfluid to said motor so that the motor may be driven in a first directionor a direction opposite said first direction.
 8. The bolter of claim 7,wherein said valve assembly includes a casing and a rotary valve memberlocated in the casing and moved angularly to provide for delivery of thedriving fluid to said motor so that said motor can be selectively drivenin either direction.
 9. The bolter of claim 7, wherein said valveincludes a movable valve member, said member valve has a drive firstposition providing for the delivery of driving fluid to drive the motorin said first direction, and a drive second position providing for thedelivery of the drive fluid to drive the motor in said oppositedirection.
 10. The bolter of claim 9, wherein the movable valve memberis movable to a third position at which the drive fluid provides for theinjection of a resin by the bolter.
 11. The bolter of claim 4, furtherincluding a lock assembly operable to engage the chuck preventingrotation thereof relative to the base.
 12. The bolter of claim 11,wherein the flow direction member includes a valve operable to activatethe motor to rotate the chuck in a predetermined direction, and alsooperable to cause engagement of the lock member to prevent rotation ofthe chuck relative to the base.
 13. The bolter of claim 12, wherein thevalve is operable to activate the motor to rotate the chuck in adirection opposite to said predetermined direction.
 14. The bolter ofclaim 2, further including an arm pivotally attached to the base forangular movement about an axis generally normal to said longitudinalaxis, with the arm including the control assembly so that an operatormay control the bolter by manipulating the arm.
 15. The bolter of claim14, including the flow direction member.
 16. The bolter of claim 15,wherein said flow direction member includes ducting to provide for theflow of the driving fluid to and from the motor.
 17. The bolter of claim15, wherein the flow direction member includes a muffler through whichdriving fluid leaving the motor is exhausted to atmosphere.
 18. Thebolter of claim 15, wherein said flow direction member includes a valveassembly to provide for the delivery of the driving fluid to said motorso that the motor may be driven in a first direction or a directionopposite said first direction, said valve assembly including a casingand a rotary valve member located in the casing and moved angularly toprovide for delivery of the driving fluid to said motor so that saidmotor can be selectively driven in either direction.
 19. The bolter ofclaim 18, wherein said valve includes a movable valve member, saidmember valve has a drive first position providing for the delivery ofdriving fluid to drive the motor in said first direction, and a drivesecond position providing for the delivery of the drive fluid to drivethe motor in said opposite direction, and the movable valve member ismovable to a third position at which the drive fluid provides for theinjection of a resin by the bolter.
 20. The bolter of claim 15, furtherincluding a lock assembly operable to engage the chuck preventingrotation thereof relative to the base, with the flow direction memberincluding a valve operable to activate the motor to rotate the chuck ina predetermined direction, and also operable to cause engagement of thelock member to prevent rotation of the chuck relative to the base and toactivate the motor to rotate the chuck in a direction opposite to saidpredetermined direction.